-For safety and maximum fuel efficiency you should check your tires regularly, paying special attention during changes of seasons or conditions that result in large temperature changes to your tires.

Accu-Pressure Safety Cap Installation Instructions
1-Unscrew and remove the existing valve stem caps (only the caps, not the stems) on your tires.
2-Make sure the O-ring seal is inside safety cap. Installation without the seal can lead to tire deflation.
3-Install a Safety Cap onto each of your valve stems by twisting in a clockwise fashion. Firmly tighten each safety cap to create a seal with the valve.
4-It is recommended that you check your installation for leaks with soapy water to insure proper seal.
5-After installation allow 30 minutes for the safety cap to display accurate pressure readings.